LIDAR (Light Detection And Ranging) is a remote sensing method of obtaining extremely detailed surface terrain data. A laser emits and receives thousands of laser pulses per second for the purpose of calculating the distance to an object. The LIDAR system (mounted to a fixed wing aircraft) consists of three main components: 1) a scanning laser rangefinder 2) a differential Global Positioning System (GPS), and 3) an Inertial Navigation System (INS). Surface elevations are derived by recording the two-way travel time of the laser pulse in combination with positioning and orientation information obtained from the onboard GPS and INS, and GPS base stations on the ground surface

Purpose:

The purpose of this project is to make images of the Bare Earth digital elevation model (DEM) derived from LIDAR

The data was collected ata density sufficient to support a maximum final post spacing of 1.4 meters for unobscured areas.

Logical_Consistency_Report:

The Light Detection and Ranging (LiDAR) LAS dataset is a topographic survey conducted for the Monroe County, Indiana. LiDAR Project consists of 525 tiles. The LiDAR point cloud was flown at a density sufficient to support a maximum final post spacing of 1.4 meters for unobscured areas. MJ Harden acquired 47 flightlines during two lifts on April 11 and Apriil 12 2010. The data was divided into 5000' by 5000' cells that serve as the final tiling scheme.

Completeness_Report:

The LAS files were flown at a density sufficient to support a maximum final post spacing of 1.4 meters for unobscured areas. The bare-earth surface will contain voids in areas that were densely vegetated, covered by bridges, buildings, water, fresh asphalt, sand etc.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Quantitative_Horizontal_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

The accuracy assessment was performed using a standard method to compute the root mean square error (RMSE) based on a comparison of ground control points (GCP) and filtered LiDAR data points. Filtered LiDAR data has had vegetation and cultural features removed and by analysis represents bare-earth elevations. The RMSE figure was used to compute the vertical National Standard for Spatial Data Accuracy (NSSDA). Ground control was established by Schneider Coorporation. A spatial proximity analysis was used to select edited LiDAR data points contiguous to the relevant GCPs. A search radius decision rule is applied with consideration of terrain complexity, cumulative error and adequate sample size. Cumulative error results from the errors inherent in the various sources of horizontal measurement. These sources include the airborne GPS, GCPs and the uncertainty of the accuracy of the LiDAR data points. This accuracy is achieved prior to the sub-sampling that occurs through integration with the inertial measurement unit (IMU) positions that are recorded. It is unclear at this time whether the initial accuracy is maintained. Finally, sample size was considered. The specification for the National Standard for Spatial Data Accuracy is a minimum of 20 points to conduct a statistically significant accuracy evaluation Most statistical texts indicate that a minimum of 30 sample points provide a reasonable Approximation of a normal distribution. The intent of the NSSDA is to reflect the geographic area of interest and the distribution of error in the data set (Federal Geographic Data Committee, 1998, Geospatial National Standard for Spatial Data Accuracy, Federal Geographic Data Committee Secretariat, Reston, Virginia, p.3-4). Additional steps were taken to ensure the vertical accuracy of the LiDAR data including: Step 1: Precision Bore sighting (Check Edge-matching) Step 2: Compare the LiDAR data to the Field Survey (Field survey is to FEMA specifications and more stringent internal specifications) Step 3: Automated Filtering Step 4: Manual Editing (Quality Control)

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value: 0.347 ft

Vertical_Positional_Accuracy_Explanation: RSME for all points report.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Publication_Date: Unknown

Publication_Time: Unknown

Geospatial_Data_Presentation_Form: vector digital data

Publication_Information:

Source_Scale_Denominator: 1200

Source_Time_Period_of_Content:

Time_Period_Information:

Multiple_Dates/Times:

Single_Date/Time:

Calendar_Date: 20100411

Time_of_Day: unknown

Single_Date/Time:

Calendar_Date: 20100412

Source_Currentness_Reference: ground condition

Source_Citation_Abbreviation: scale map

Source_Contribution:

The Light Detection and Ranging (LiDAR) LAS dataset is a topographic survey conducted for Monroe County, Indiana. LiDAR Project consists of 134 tiles. The LiDAR point cloud was flown at a density sufficient to support a maximum final post spacing of 1.4 meters for unobscured areas. MJ Harden acquired 47 flightlines during two lifts on April 11 and Apriil 12, 2010. The data was divided into 5000' by 5000' cells that serve as the final tiling scheme.

Process_Step:

Process_Description:

The Airborne Global Position System (ABGPS), inertial measurement unit (IMU), and raw scans are collected during the LiDAR aerial survey. The ABGPS monitors the xyz position of the sensor and the IMU monitors the orientation of the aircraft. During the aerial survey laser pulses reflected from features on the surface and are detected by the receiver optics and collected by the data logger. GPS locations are based on data collected by receivers on the aircraft and base stations on the ground. The ground base stations are placed no more than 20 km radius from the flight survey area.

Source_Used_Citation_Abbreviation: Optech Gemini

Source_Used_Citation_Abbreviation: Airborne Global Positioning System

Source_Used_Citation_Abbreviation: Inertial Measuring Unit

Source_Used_Citation_Abbreviation: Global Positioning System

Process_Date: 20100411

Source_Produced_Citation_Abbreviation: LiDAR Scan Files

Source_Produced_Citation_Abbreviation: LiDAR Scans, GPS data

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: MJ Harden

Contact_Address:

Address_Type: mailing and physical address

Address: 5700 Broadmoor, Suite 800

City: Mission

State_or_Province: Kansas

Postal_Code: 66202

Country: USA

Contact_Voice_Telephone: (913) 981-9600

Contact_Facsimile_Telephone: (913) 981-9602

Hours_of_Service: 8:00 - 5:00 CDT

Process_Step:

Process_Description:

The ABGPS, IMU, and raw scans are integrated using proprietary software developed by Optech the and delivered with the Optech Gemini System. The resultant file is in a LAS binary file format. The LAS file version 1.2 format can be easily transferred from one file format to another. It is a binary file format that maintains information specific to the LiDAR data (return#, intensity value, xyz, etc.). The resultant points are produced in the Indiana State Plane West Zone coordinate system, with units in feet and referenced to the NAD83 horizontal datum and NAVD88 vertical datum.

The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters is applied as appropriate for the production of bare-earth digital elevation models (DEMs). Interactive editing methods are applied to those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces.

Source_Used_Citation_Abbreviation: Point Cloud LiDAR LAS 1.2 format

Process_Date: Unknown

Source_Produced_Citation_Abbreviation: Filtered Data LiDAR datasets

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: MJ Harden

Contact_Address:

Address_Type: mailing and physical address

Address: 5700 Broadmoor

City: Mission

State_or_Province: Kansas

Postal_Code: 66202

Country: USA

Contact_Voice_Telephone: (913) 981-9600

Contact_Facsimile_Telephone: (913) 981-9602

Hours_of_Service: 8:00 - 5:00 CDT

Process_Step:

Process_Description:

Filtered and edited data are subjected to rigorous QA/QC according to the MJ Harden Quality Control Plan and procedures. Very briefly, a series of quantitative and visual procedures are employed to validate the accuracy and consistency of the filtered and edited data. Ground control is established by MJ Harden. and GPS-derived ground control points (GCPs) points in various areas of dominant and prescribed land cover. These points are coded according to landcover, surface material and ground control suitability. A suitable number of points are selected for calculation of a statistically significant accuracy assessment as per the requirements of the National Standard for Spatial Data Accuracy. A spatial proximity analysis is used to select edited LiDAR data points within a specified distance of the relevant GCPs. A search radius decision rule is applied with consideration of terrain complexity, cumulative error and adequate sample size. Accuracy validation and evaluation is accomplished using proprietary software to apply relevant statistical routines for calculation of Root Mean Square Error (RMSE) and the National Standard for Spatial Data Accuracy (NSSDA) according to Federal Geographic Data Committee (FGDC) specifications.

The LiDAR mass points were delivered in American Society for Photogrammetry and Remote Sensing LAS 1.2 format. The header file for each dataset is complete as define by the LAS 1.2 specification. In addition the following fields are included: Flight Date Julian, Year, and Class. The data were classified as follows: Class 1 = Unclassified- this class includes vegetation, buildings, noise etc.; Class 2 = Ground; Class 7 = Noise; Class 9 = Water; Class 12 = Overlap. The datasets were delivered in the 5000' by 5000' tiling scheme. The tiles are suitable for seamless topographic data mosaics that include no "no data" areas. Tile layout created by MJ Harden.

Unrepresentable_Domain: The date the feature was exported to ASCII xyz format

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Address:

Address_Type: mailing and physical address

Resource_Description: Downloadable Data

Distribution_Liability:

The data represent the results of data collection and processing for a specific activity and indicates the general existing conditions at the time of the data collection. As such, it is only valid for its intended use, content, time, and accuracy specifications. The user is responsible for the results of any application of the data for other than its intended purpose.